Correct. The space shuttle accelerated to over 3000mph when the boosters disconnect. In orbit, the shuttles fly at over 17000 mph. At sea level, approximately 750 mph is the speed of sound or around 1100 fps. Supersonic is anything above the speed of sound, hypersonic is commonly considered 5x the speed of sound (mach 5+). Speed of sound is actually different values at different altitudes, but 750mph x 5 is a good place to estimate. 3750mph or higher is hypersonic. A missile can be accelerated much faster without a human payload which limits acceleration due to lethal G forces. Hypersonic missiles are not new. We just didnt expect the chinese to make an ICBM because the intelligence agencies were unaware of the program. Either the Chinese are better at keeping secrets on a huge program, or our intelligence agencies didn't report on it.